After translating the document (or in case I receive an already translated file), to review the translation I pass from one segment to the other.
When I go to next segment (Alt+DownArrow) the TM is retrieved and the segment is modified according to the TM, although I've another transaltion in that segment which should remain as is and not comply with the TM.
I would like the TM remains just a proposal (such as other CATs) and let me decide wheather to implement the proposed TU or leave it as is.
Is there a way for this? Or maybe lock them?
Try navigating using Ctrl (or Cmd if on a Mac)+Down Arrow instead of Alt+Down arrow and activate "Perform TM Lookup automatically under Preferences > Translation Memory. This should resolve your problem.
A second thing, always concerning TM.
In a document folder a Fuzzy TM was created. Is it related to the "Write unedited fuzzy and exact segments to a TM"?
I don't quite understand the situation.